Friday, February 3, 2012

Mountains Under A Microscope

There are a lot of intriguing ideas and concepts in geology. Some are easier to wrap our minds around than others. One of the most phenomenal has got to be the idea that a 3 inch x 1 inch glass slide with a sliver of rock attached that has been sawed, sliced, glued and polished to a thickness of 0.03 millimeter can provide clues to the history of an entire mountain range. 

That’s 0.00118110236 of an inch of rock on a glass slide. Put under a special type of petrographic microscope and studied, this rock sliver or thin section can offer unparalleled insight not only to a mountain range but to the tectonic history of an entire continent.

Which means that knocking off a fist–sized piece of rock from someplace like this…

Beaver Dam Mountains in southwest Utah

…and sawing, slicing, and then gluing a sliver onto one of these…

web image courtesy here

…and then polishing this sliver to within 0.00118110236 of an inch of its life so that you see something like this…

Sheared bands in gneiss with C–S fabrics in cross-polarized light

…can provide us phenomenal insight into how and when this came into existence.

Beaver Dam Mountains in southwest Utah


  1. I would love to see a sliver of every rock I own under that kind of microscope. So cool!

    I did see a friends boulder opals under a scope recently and it was like visiting another world.

  2. Gaelyn - Yes indeed these slides are yet another window into a fascinating world.